During root canal therapy, an endodontic procedure, it is necessary for the professional (a dentist or endodontist) to use a number of instruments. In particular, instruments are employed by the dental professional to remove pulp tissues from the root canal once the pulp chamber is exposed.
Typically, such instruments, such as files, comprise a thin, flexible, metal shaft or file with an abrasive surface or sharp edges. A handle or hub end is attached on one end of the instrument and may be gripped by the dental professional or attached to a drill. Such instruments also include the bits of drills.
The instruments are inserted into a canal of the tooth during root canal therapy. In order to prevent penetration of such instruments beyond the canal apex, the file must be inserted no more than a specific distance inside the canal of the tooth. A determination must be made as to how far the file instrument can enter the canal prior to the insertion. Commonly, an adjustable stopper is placed over each file instrument along the shaft or file so that the distance between the tip of the instrument and the stopper is the same as the distance between the top surface of the tooth and the apex of the canal. Thus, the working length of the file is established.
During the root canal therapy, the application of medicament or a sterilizing solution to the file instrument is usually necessary. At all times, the hygiene of the entire system is of paramount concern. The ease with which used instruments may be collected for cleaning after a procedure without causing damage to the instruments and injury to the collector is also of concern.
U.S. Pat. No. 4,976,615 (Kravitz) is an example of an attempt to address some of the needs of the dental professional in the form of a platform adapted to be mounted on a dentist's finger. A foam insert holder mounted on the platform receives a removable foam insert for holding a plurality of root canal instruments. An open-ended slot formed in the platform is adapted to receive one of the instruments. Scale indicia is provided on the platform to permit adjustment of the working length of the file instrument in the slot to guide the dentist.
However, the platform in Kravitz is designed to receive a removable foam insert and hence to be re-usable; the other parts of the platform must be sterilized each time the platform is re-used; to dispose of the platform after each use is expensive. It also fails to provide means to hold medicament for the dental professional.
The platform disclosed in U.S. Pat. Nos. 5,368,482 and 6,036,490 (Johnsen et al.) includes a resiliently deformable cushion in a socket member. The cushion provides surface regions configured to receive endodontic instruments. The platform may be used to service the files. A finger mount is attached to the socket member. The platform may include a ruler. The description of a commercial version of this platform may be found at http://www.jordco.com.
This cushion of this platform is essentially rectangular in shape. This appears to be too narrow and offers insufficient space for a larger array of endodontic instruments. The drawings of the platform shows the usage of up to 10 such instruments; in practice, an endodontist may use up to 20 instruments on a single canal of a tooth. The drawings of this platform also show a medicament holder of a volume that is indicative of wastage of medicament.
Furthermore, this design is geared to be held by a single finger of the endodontist. Thus most of the work, e.g. determining the working length, choosing the correct instrument, etc., has to be done by the endodontist alone; a chairside assistant can help very little. The design is incompatible with teamwork and wastes the doctor's chair-time. Another drawback of the single finger-mounted design is the strain it imposes on the endodontist. The platform and the instruments it hold can be of sufficient weight that it becomes tiring and wearying for a carrier of such platforms in the course of a single endodontic procedure (one or more hours). Cross-contamination becomes a serious problem since the endodontist needs to record working length separately and contact other unsterilized material during the procedure. Cross-infection is also a serious issue in the case where a ruler is used and different cushions are deployed for different canals, at least one of which is infected. The infection spreads by use of the common ruler. Thus the hygienic state of the platform may be compromised in a number of ways.
U.S. Pat. No. 6,681,925 (Fischer et al.) is an autoclavable and resealable endo file container with an open ended including a body and a lid for closing the container. The lid is also configured for stabilizing the container in an upright position when the lid is placed over the bottom of the container. The lid is flared and generally provides greater support to the container for standing upright than does the bottom of the container. A foam material (e.g., open cell foam) housed within the container is used to hold dental instruments. A disinfecting solution contained within the container disinfects any dental instruments held therein.
The container disclosed in Fischer et al. has a number of disadvantages. It is designed to be re-used as in the case of the Kravitz platform; although it provides means for disinfecting instruments, the instrument must be placed in the foam material to receive the disinfectant.